<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body>

<div ng-app="myApp" ng-controller="myCtrl">
    <p>{{ x1 }}</p>
    <p>{{ x2 }}</p>
</div>

<script>
    var app = angular.module('myApp',[]);
    app.controller('myCtrl', function ($scope) {
        $scope.x1 = "JOHN";
        $scope.x2 = angular.isNumber($scope.x1);
    });
</script>
</body>
</html>